The present invention relates to a method of producing an odorless ripe juice containing the components of Houttuynia cordata (referred to as "dokudamiso" hereinafter), which have medicinal effects, from raw dokudamiso.
Dokudamiso contains abundant amounts of quercitrin, which is a flavonol glucoside having a cardiotonic function, an intestine regulating function, a blood pressure regulating function and a detoxicating function, and other components having medicinal effects. Dokudamiso has been therefore used as a folk medicine for a long time. As is generally known, however, dokudamiso has a strong, unpleasantly peculiar odor. To use it, it is therefore necessary to extract the quercitrin from dokudamiso by squeezing or leaching and then to decompose or remove the odor components.
It is known that the odor components of dokudamiso are laurin aldehyde and caprin aldehyde, which are irrelevant to the medicinal effects thereof and which can be substantially completely removed by drying or steam distillation. In most cases, dokudamiso is therefore utilized through the internal use of an odorless exudate obtained by a method of decocting dry dokudamiso. Although this method has an advantage in that the effective components of dokudamiso can be used throughout all seasons if dry dokudamiso only is prepared, it is tedious to decoct dry dokudamiso for each internal use of the odorless exudate.
A method of utilizing dokudamiso without drying is proposed in which a dokudamiso green juice is deodorized and then internally used (Japanese Patent Publication No. 59-7692). In the deodorizing method, a yeast and a carbon source therefor are inoculated into the dokudamiso green juice, which is then fermented, and the thus-obtained suspension is filtered. In this method, however, since the odor components of dokudamiso are decomposed or converted into odorless compounds during the process of alcoholic fermentation using a yeast, deodorization takes much time, and it is necessary to be extremely careful regarding the management of the alcoholic fermentation process so as to prevent putrefaction and the occurrence of mold. This method also has the problem that, since the deodorized dokudamiso juice contains alcohol in a content substantially the same as that in alcoholic beverages, the juice becomes hard to drink for the aged or infant.
Accordingly, it is an object of the present invention to provide a method of producing a dokudamiso juice by which dokudamiso green juice can be deodorized by a deodorizing method without using alcoholic fermentation to improve the taste and provide the effective components of dokudamiso in a form which allows them to be drunk easily.
It is another object of the present invention to provide a method of effectively producing in a short time a dokudamiso juice which is suitable for drinking and which contains the dokudamiso components having medicinal effects.